Vilistextum is a small and fast HTML to text converter. It is quite fault-tolerant and deals well with badly-formed or otherwise quirky HTML. It has full support for different character sets (e.g. Unicode). It is able to optimize for ebook reading, collapse multiple blank lines, and create footnotes out of links. A GUI frontend using kaptain is included.

TEA is a powerful and easy-to-use Qt4-based editor
with many useful features for HTML, Docbook, and
LaTeX editing. It features a small footprint, a
tabbed layout engine, support for multiple
encodings, code snippets, templates, customizable
hotkeys, an "open at cursor" function for HTML
files and images, miscellaneous HTML tools,
preview in external browser, string manipulation
functions, Morse-code tools, bookmarks, syntax
highlighting, and more.

Docvert is Web service software that takes
multiple word processor files (typically .doc) and
converts them to Oasis OpenDocument v1.0 format,
and then optionally to any XML/HTML format. The
results are returned in a .zip file.

gjots lets you organize text notes in a convenient, hierarchical way. It can be used for notes, jottings, bits and pieces, recipes, and even PINs and passwords, using encryption. It can also be used to "mind-map" larger compositions like manuals, Web pages, articles, etc. It is a bit like the KDE program "kjots", but uses the GTK library and supports a hierarchy of folders. Files can be output to HTML with an automatic table of contents or to docbook XML. Encryption is supported with ccrypt(1), gpg(1), and openssl(1), so that musings can be kept private.

Xidel is a command line tool to download Web pages and extract data from them. It can download files over HTTP/S connections, follow redirections, links, or extracted values, and process local files. The data can be extracted using XPath 2.0, XQuery 1.0, and JSONiq expressions, CSS 3 selectors, and custom, pattern-matching templates that are like an annotated version of the processed page. The extracted values can then be exported as plain text/XML/HTML/JSON, or assigned to variables to be used in other extract expressions or be exported to the shell. There is also an online CGI service for testing.

The SeaMonkey project is a community effort to develop an all-in-one Internet application suite. It contains an Internet browser, email and newsgroup client with an included Web feed reader, HTML editor, IRC chat, and Web development tools, and is sure to appeal to advanced users, Web developers, and corporate users. It uses much of the Mozilla source code powering such successful siblings as Firefox, Thunderbird, Camino, Sunbird, and Miro.

htmLawed is a PHP script that makes input text
more secure, HTML standards-compliant, and
suitable in general from the viewpoint of a
Web-page administrator, for use in the body of
HTML 4 or XHTML 1 or 1.1 documents. It is a
customizable HTML/XHTML filter, processor,
purifier, and sanitizer. It can ensure that HTML
tags are balanced and properly nested tags,
neutralize code that may be used for cross-site
scripting (XSS) attacks, and limit the allowed
HTML elements, tags, attributes, or URL protocols.

GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.